Firewall opinions wanted please

On Wed, Mar 17, 2004 at 08:54:57AM -0800, bill said something to the effect of:
> > > The best option I guess is to figure out how important it is for you to have a firewall,
> >
> > _Everyone_ (network connected) should have a firewall. My grandma should
> > have a firewall. Nicole, holding dominion over this business network and
> > its critical infrastructure, should _definitely_ have a firewall. :wink:
> >
> Why? When did the end2end nature of the Internet suddenly
> sprout these mutant bits of extra complexity that reduce
> the overall security of the 'net?
> Two questions asked, Two answers are sufficent.

Nope. One will do it. The day the first remote exploit or condition,
in protocol or application, that could potentially have given rise to such
and exploit made it possible for a user not in your control to gain control
of your box(en), firewalling became necessary.

  Ah, so back in 1979. Three (well two and a half, roughly)
  decades between making fundamental design choices on how
  protocols vs folks trying to do the right thing in the wrong

Then Internet is not exactly
end-to-end beyond pure fundamentals; it's more end-to-many-ends. And the
notion of "end-to-end" requires preservation of a connection between 2
consenting hosts, and preservation includes securement of that connection
against destructive mechanisms, which includes the subversive techniques and
intercetptions commonly associated with network security.

  Here we have some disagreement. Network Security is protecting
  the infrastructures ability to deliver bits and has nothing to
  do w/ end systems per se.

Firewalls are logical interventions, costing as little as some processor
overhead. Dedicated appliances are only one deployment. Filters on
routers also qualify as firewalls. Am I correct in understanding that you
feel edge filtering is mutant lunacy and unnecessary complexity?

  Please include the OPEX costs. And you have ignored the
  IAB plea for having filtering done as a temporary expdient
  as a way to encourage new application/feature development.
  And yes, the need to perform edge filtering is symtematic of
  a cultural problem. We have sociopaths in the community that
  drive normally sane people to do perverse things.

  So yes, mutant lunacy and unDESIRABLE complexity.

Regarding dedicated firewalls, please see Mr. Bellovin's previous post
regarding appropriate and competent administration. The lack thereof
presents the complication, not the countermeasure itself.

  Amen. See above. From a systems perspective, adding yet
  one more level of management/administration decreases the
  efficentcy and robustness of the overall system. From a
  "security" perspective, another attack point!

As for your assertion that firewalls "reduce the overall security of the
'net."...can you please elaborate on that, as well? Other factions might/do
argue that it's the other team refusing to lock their doors at night that
are perpetuating the flux of bad behavior as a close second to the ignorant
and infected.

  See above.